Signals
3FDA approves leucovorin calcium as first treatment for CFD-FOLR1
The FDA has approved expanded use of Wellcovorin (leucovorin calcium) tablets for cerebral folate deficiency caused by confirmed FOLR1 gene variants, marking the first approved treatment for this rare neurological condition in adults and children.
Real-world ARIA rates from registries are landing close to trial estimates
Early registry data on lecanemab and donanemab in routine clinical use is producing ARIA incidence numbers that broadly track the pivotal trials, with APOE4 homozygotes consistently the highest-risk group.
APOE4 genotype is reshaping eligibility, dosing, and disclosure
Anti-amyloid trial readouts and post-marketing surveillance both show APOE4 homozygotes face higher ARIA risk - pushing genotype testing into pre-treatment workflows.
Explained
2What ARIA is, and why it gates how anti-amyloid antibodies can be used
ARIA - amyloid-related imaging abnormalities - is the side effect that defines the operational and clinical experience of being on lecanemab or donanemab. Understanding what it is, who it affects more, and why it requires MRI surveillance is essential context for any conversation about anti-amyloid treatment.
Why APOE4 matters in Alzheimer's disease and treatment
APOE4 is both the strongest common genetic risk factor for late-onset Alzheimer's and a meaningful modifier of treatment safety - which is why genotyping is now part of the workup.